A variety of fixation devices for the reduction of bone or bone fragments are well known. Some fractures, including wrist fractures, can be difficult to align and treat. Alignment and fixation have been typically performed by one of several methods, including casting, external fixation, and interosseous wiring. Casting is noninvasive, but may not be able to maintain alignment of the fracture where many bone fragments exist. Therefore, as an alternative, external fixators may be used. External fixators utilize a method known as ligamentotaxis, which provides distraction forces across the joint and permits the fracture to be aligned based upon the tension placed on the surrounding ligaments. However, while external fixators can maintain position, it may nevertheless be difficult in certain fractures to first properly align the bones. In addition, external fixators are often not suitable for fractures resulting in multiple bone fragments. In addition, external fixation is associated with reflex sympathetic dystrophy, stiffness, and pin complications. Moreover, with some fractures, movement helps to facilitate rehabilitation, and this movement is prevented by external fixation. Interosseous wiring is an invasive procedure whereby screws are positioned into the various fragments and the screws are then wired together as bracing. This is a difficult and time consuming procedure. Moreover, unless the bracing is quite complex, the fracture may not be properly stabilized.
As a result, fixation of fractures, including those of the wrist have more recently been performed using bone fixation plates. Attachment of a bone fixation plate to a fractured bone is accomplished by first reducing the fracture fragment(s) and subsequently attaching the bone fixation plate to the bone on opposite sides of the fracture site(s) using bone screws or the like. It is therefore important in many instances to ensure that the bone fixation plate is properly positioned on the bone to ensure that the bone fragment(s) are adequately reduced. Thus, the bone fixation plate is temporarily affixed to the bone, and a medical image (e.g., X-ray) determines whether the fracture site is adequately reduced before the bone fixation plate is permanently affixed to the bone.
Several systems are being used to temporarily affix a bone fixation plate to an underlying fracture bone to determine proper reduction prior to permanent plate fixation. For instance, in one system, a K-wire is screwed or otherwise driven through the screw holes of the plate on opposite sides of the fracture. The K-wire is smaller in diameter than the screw holes, and is thus positioned so as to bear against opposing edges of the respective screw holes so as to prevent movement of the plate during imaging. The process of accurately positioning the K-wire so as to prevent movement of the bone fixation plate has proven difficult and tedious, as any space between the K-wire and the outer edge of the screw hole will allow movement. In another system, holes are pre-drilled in the bone, and a cortex (e.g., non-locking) screw is inserted through the screw hole and into the pre-drilled hole in the bone. Unfortunately, several unnecessary holes are drilled in the bone as the bone fixation plate is repositioned. In yet another system, holding clamps attach to the bone fixation plate and are invasively fitted around the bone.